Culture name 'xxx' is not supported

installed blogengine 2.0. Deleted the previus version 1.5. Updated database with scripts. Blog works until I change the config to the one from MSSQL.

Then I get Culture name error.

If I go direct to admin pages - they work, I can even change the existing posts or write new ones, but when I want to see it (preview of frontend), the error is the same.

Any help fixing the problem would be wery nice.

Thanks!

Error details:

Culture name 'si-sl' is not supported.
Parameter name: name

Description:
An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentException: Culture name 'si-sl' is not supported.
Parameter name: name

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.